We are mobilizing an army of lawyers to help families that were unlawfully separated or detained by the Trump administration.

President Trump’s recent executive order ending the unlawful and immoral policy of separating children from their parents advances another, equally lawless policy: prolonging the detention of families seeking asylum.

In his June 20 order, Mr. Trump pinned the current crisis on bad law, specifically citing “Congress’s failure to act and court orders.” On Sunday, the President went even further, suggesting that the United States suspend due process for undocumented immigrants altogether: “When somebody comes in, we must immediately, with no judges or court cases, bring them back from where they came.”

The problem, of course, is neither United States law nor the Constitution. It is the administration’s belief that both can be ignored to achieve a political end. As long as this administration pursues a deterrence policy predicated on inflicting harm on children and families and disregarding settled constitutional principles, the crisis will continue.

The president’s executive order is silent on how to help the more than 2,000 children, including infants and toddlers, who have already been separated from their parents and are now in federal custody. Held in an estimated 100 shelters around the country, these children remain in limbo, with no plan for reunification. The longer they are separated from their parents, the more severe and indelible the psychological toll. The continuing separation violates the constitutional guarantee of family integrity, which prevents the government from taking children from their parents without due process.

The executive order’s proposed alternative of prolonged family detention fares no better as a legal matter. Flores v. Reno, a 1997 case challenging conditions for children in immigration custody, expressly prevents immigration officials from detaining children for longer than 20 days. In another case, R. I. L-R v. Johnson, the Federal District Court for the District of Columbia in 2015 ordered the government to stop basing its detention policies for parents and children on its goal of deterring immigration.

Equally troubling, the administration’s avowed policy of prosecuting every person who illegally crosses the border, no matter their circumstance, contravenes our international treaty obligations. Many of these families are escaping unimaginable persecution in their home countries.

The 1951 Convention on the Status of Refugees, which the United States helped draft and subsequently ratified in the aftermath of World War II, prohibits parties to the treaty from imposing “penalties, on account of their illegal entry or presence, on refugees who, coming directly from a territory where their life or freedom was threatened” or who “enter or are present in their territory without authorization, provided they present themselves without delay to the authorities and show good cause for their illegal entry or presence.”

Moreover, the administration’s policy of detaining families, like the child separation policy that preceded it, applies not only to those who cross between points of entry but also to those who obey our laws to the letter and present themselves at a point of entry to claim asylum.

We speak for a group of lawyers who lead 34 major American law firms. As a group, we cannot stand by as our government, under the pretext of enforcing the law, violates it and traumatizes children and their parents in the process. We are professionally obligated to safeguard the rule of law and to protect the poor and the vulnerable against targeted governmental abuses. We call upon the administration to develop an immediate plan for reunifying children with their families, to release families who pose no threat to our country and to terminate the policy of criminally prosecuting asylum seekers.

While it is the government’s responsibility, ultimately, to solve problems of its own making, we have coalesced our resources and joined forces with the legal services community to protect the rule of law. Our firms, which collectively employ about 30,000 lawyers in nearly every state, have pledged to help reunify families and ensure representation for legitimate asylum seekers. This outpouring of volunteerism depends on strong partnerships with the legal services entities on the front lines. The firm Paul, Weiss, working with the Refugee and Immigrant Center for Education and Legal Services, has sent a team of lawyers to represent parents detained near the border in Texas. The Lowenstein Sandler firm has been working alongside the Vera Institute of Justice and the Young Center for Immigrant Children’s Rights to secure access to counsel for the young, separated children held in New York State and to advise lawyers of their ethical obligations when they undertake such representation.

This crisis requires an army of lawyers to untangle because the immigration courts are flooded and detention centers across the country are bursting. The world is watching, and the private bar is mobilizing to serve the thousands who have been imperiled by the Trump administration — and to ensure that the rule of law is protected as well.